Efforts are underway to develop hydrogen as a future transportation fuel, but today, it is mostly used to produce other chemicals (60% for ammonia; 23% for capture and use in oil refineries, 9% for methanol production). The U.S. consumes about 20% of world production.
Hydrogen is made from syngas (a gaseous mixture of mostly carbon monoxide and hydrogen) which is produced from the gasification of feedstocks at high temperatures under conditions where the amount of oxygen is less than what is needed for complete combustion. Syngas can be produced from many feedstocks including natural gas, petroleum products, coal and biomass. Under today’s conditions, natural gas is the least expensive feedstock and 77% of the world hydrogen production uses natural gas and 18% uses coal.
Metal catalysts are used to convert the syngas to hydrogen. High sulfur levels in syngas can poison the catalysts. Numerous hydrogen reactor designs exist and can be used in a number of process configurations.
Average purchase prices for large-volume, bulk deliveries of hydrogen range from $18-$24/GJ ($19 to $25.35/MBtu). The cost of producing hydrogen from natural gas in large-scale, central production facilities is estimated to be about $5-$8/GJ ($5.30 to $8.45/MBtu).
Hydrogen itself is a clean burning fuel. However, depending upon the feedstock used, its production can generate CO2 and NOx.